Successional Communities of Plants and Phytophagous Coleoptera

Abstract

(1) A secondary succession on sandy soil in southern England is represented by seven experimental sites of known successional age, from the colonization of bare ground, through permanent pastureland to birch woodland. The development of the sites over 5 yr is described. (2) Communities of plants and phytophagous Coleoptera (weevils and leaf beetles) from sites of different successional age are defined using reciprocal averaging ordination. (3) The successional communities of phytophagous beetles are characterized by a sequence of dominant species, with the highest dominance occurring during very early colonization and mid-late succession; a pattern also seen in the herbs. (4) The species diversity of herbs and weevils is closely related throughout the succession. It is suggested that plant-species composition may be more important than plant structure in solely phytophagous groups of insects. (5) The host-plant associations of weevils and leaf beetles are discussed in terms of generalism-specialism and niche breadth. Measures for these are described. (6) The occurrence of a higher degree of generalism in weevils in late succession, than predicted in certain models of succession, is explained in terms of Rhoades' and Cates' theories of plant anti-herbivore chemistry.